Scarabs of this type, with generalised hieroglyphs and geometric patterns, were popular during the Middle Kingdom. They gain popularity especially during late Dynasty 12 to Dynasty 13, circa 1850–1640 BC. However influence was taken from such designs during the New Kingdom, when geometric patterns also became popular. Scarabs such as these would have been worn for their apotropaic value.
To find out more about Ancient Egyptian amulets please see our relevant blog post: Egyptian Amulets and their Meanings.